Water scarcity limits irrigated agriculture, and there is an increasing frequency of situations where farmers must transition from irrigated to dryland cropping systems. This transition poses several challenges, and it is necessary to understand the changes in crop productivity and soil health for the design of viable cropping systems. Our objective was to compare the impact of irrigation retirement on crop production and soil microbial dynamics under the two major crops of the semiarid High Plains. In a formerly irrigated field, we installed a transition experiment that consisted of two irrigation managements, irrigated and non-irrigated (retired), under two cropping systems: continuous maize and continuous winter wheat. Lower soil moisture after irrigation retirement decreased plant biomass production in both crops, with a higher effect on maize (2 to 6-fold decrease) than on wheat (20% less aboveground biomass production). In both crops, irrigation retirement affected crop development in the order grain yield > aboveground biomass > belowground biomass. Soil microbial communities were less affected by irrigation retirement than the evaluated crops and changes were concentrated in the maize agroecosystem. After three seasons, the high decrease in maize productivity and soil moisture resulted in 50% less extracellular enzyme activity in the dryland treatment, but without consistent effects on microbial biomass or community composition assessed by phospholipid fatty acids. Winter wheat appears as a viable option not only to sustain crop production but also to minimize the negative impacts of irrigation retirement on soil health. However, root production was lower in wheat than in maize, which may affect the long-term evolution of soil organic carbon.
Rice (Oryza sativa L.), Cultivar Caloro, was harvested at 13 levels of moisture content in the grain beginning at 43% and ending at 13%. Seed yields increased rapidly as grain moisture decreased from 43 to 31%. They increased slowly between 31 and 19%, but remained constant thereafter. Weight per seed and liter weight followed the same trend as seed yields. Germination percentage increased steadily as grain moisture decreased. Speed of emergence of seedlings through 10 cm of water was faster when grain was harvested below 20% moisture. Shoot length of seedlings grown on blotters held at a 67° angle in a germinator indicated earlier and faster growth as grain moisture decreased to 13%. Resistance of seedlings to the water mold (Achlya klebsiana Pieters) was optimum when grain was harvested at 13% moisture.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.